Prasad M L, Osborne M P, Hoda S A
Department of Pathology, New York Hospital-Cornell Medical Center, New York, USA.
Anat Pathol. 1998;3:209-32.
Our histopathologic criteria for diagnosing microinvasive carcinoma of the breast may be enunciated as follows: (1) cytologically malignant cells in the stroma associated with in situ carcinoma, (2) absence of basement membrane and myoepithelial cells around the invasive cells, (3) frequent accompanying stromal alterations in the form of myxomatous change and loosening of connective tissue, and (4) the frequent presence of an inflammatory cell infiltrate composed of lymphocytes and plasma cells. Most or all of these four features are present in cases of ductal microinvasive carcinoma of the breast, but the lobular type is not likely to be accompanied by stromal changes or a lymphoplasmacytic cell infiltrate. The minimum information regarding microinvasive carcinoma of the breast that should be conveyed in the final pathology report includes size as measured by the ocular micrometer or a statement that microinvasion refers to a lesion smaller than 1 mm, the number of foci of invasion, and the spatial distribution of the invasive foci. The nuclear grade of the invasive cells and the size, type, and nuclear grade of the accompanying DCIS should be specified. The status of margins, presence of vascular channel involvement (a rarity in microinvasive carcinoma of the breast), and degree of proliferative changes in adjacent nonneoplastic breast tissue should be reported. Immunostains for basement membrane and myoepithelial cells may be helpful in the diagnosis of microinvasive carcinoma of the breast. Sclerosing lesions such as radial scar and sclerosing adenosis can simulate microinvasive carcinoma of the breast, especially when the latter is associated with in situ carcinoma. Caution should be exercised in cases wherein in situ malignant cells may be dislodged by needling procedures or during dissection of the excised specimen. Cautery-induced artifacts also hinder optimal histologic assessment. In some cases, it is virtually impossible to determine if true invasion is present, and the statement "microinvasive carcinoma of the breast cannot be entirely excluded" may be employed as a last resort. We consider the latter diagnosis to be the last refuge of the diligent pathologist and do not recommend it unless all diagnostic measures, including examination of deeper levels and supplemental stains, have been exhausted. It may be necessary to seek an expert opinion in "difficult" cases, particularly in the event that therapeutic decisions are to be based on the determination of invasion. From a clinical perspective, the management of microinvasive carcinoma of the breast ought to be dictated by the individual circumstances in each case. Based on currently available data, which admittedly suffer from lack of diagnostic uniformity, the vast majority of patients with microinvasive carcinoma of the breast will be node-negative and can look forward to an excellent prognosis. It is hoped that since the UICC has adopted a previously recommended definition of microinvasive carcinoma of the breast, prospective or retrospective studies with uniform diagnostic criteria will be conducted that will enable more definitive conclusions regarding the treatment and prognosis of microinvasive carcinoma of the breast.
（1）与原位癌相关的间质中存在细胞学上的恶性细胞；（2）浸润细胞周围不存在基底膜和肌上皮细胞；（3）常伴有黏液样变和结缔组织疏松等间质改变；（4）常存在由淋巴细胞和浆细胞组成的炎性细胞浸润。乳腺导管微浸润癌病例大多或全部具备这四个特征，但小叶型不太可能伴有间质改变或淋巴浆细胞浸润。最终病理报告中应传达的关于乳腺微浸润癌的最少信息包括用目镜测微计测量的大小，或说明微浸润指的是小于1mm的病变、浸润灶的数量以及浸润灶的空间分布。应明确浸润细胞的核分级以及伴发的导管原位癌的大小、类型和核分级。应报告切缘情况、血管腔受累情况（乳腺微浸润癌中少见）以及相邻非肿瘤性乳腺组织的增殖性改变程度。基底膜和肌上皮细胞的免疫染色可能有助于乳腺微浸润癌的诊断。诸如放射状瘢痕和硬化性腺病等硬化性病变可模拟乳腺微浸润癌，尤其是当后者与原位癌相关时。在原位恶性细胞可能因穿刺操作或在切除标本解剖过程中脱落的情况下应谨慎。烧灼引起的人为假象也会妨碍最佳的组织学评估。在某些情况下，实际上无法确定是否存在真正的浸润，作为最后手段可采用“不能完全排除乳腺微浸润癌”的表述。我们认为后一种诊断是勤勉的病理学家的最后庇护所，除非包括更深层次检查和补充染色在内的所有诊断措施都已用尽，否则不建议使用。在“困难”病例中，可能有必要寻求专家意见，特别是在治疗决策要基于浸润的判定时。从临床角度看，乳腺微浸润癌的治疗应根据每个病例的具体情况决定。根据目前可得的数据，诚然这些数据缺乏诊断一致性，绝大多数乳腺微浸润癌患者将无淋巴结转移，有望获得良好预后。希望由于国际抗癌联盟（UICC）采用了先前推荐的乳腺微浸润癌定义，将开展具有统一诊断标准的前瞻性或回顾性研究，从而能够就乳腺微浸润癌的治疗和预后得出更明确的结论。
